Telephone-transmitter



(No Model.)

J. A. LAKIN.

' TELEPHONE TRANSMITTER? No. 279,401. Patented June 12,1883.

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UNITED STATES PATENT OFFICE.

JAMES A. LAKIN, OF WESTFIELD, MASSACHUSETTS.

TELEPHONE-*TRANSMITTER.

SPECIFICATION forming part of Letters Patent No. 279,401, dated June 12, 1883.

Application filed March 9. 1853. (No model.)

To all whom, it may concern:

Be it known that I, JAMES A. LAKIN, of \Vestfie] d, in the county of Hampden and State of Massachusetts, have invented a new and useful Improvement in Telephone-Transmitters, of which the following a description and specification.

The object of my invention is to provide a telephonic transmitter in which a floating electrode and pivoted arm are used to furnish re sistance to the vib 'ations of the contactpoint located in rear of and operating against the diaphragm or a carbon button secured thereto;

and I accomplish this by the mechanism sub-.

' in the usual manner, and with a carbonbutton,

6, attached to the rear side of the diaphragm. I attach a bracket, 16, to the metallic diaphragm-fran1e,.or to any convenient point 011 the inside of the door, and which bracket I make forked, or with two arms, and with center points or pivots, as at 15, at the end of each arm, said pivots each consisting preferably of a pointed screw, 15, turned through athreaded hole in the end of each arm. An arm, 1.1, is hung or pivoted at one end between these pivots or centers 15, and extends rearward, and from the pivoted end of this arm, and to which it is secured, a spring, 9, extends upward, with a small weight and a metallic contact-point secured to its upper end in a positionjust in rear of the diaphragm and the carbon button at tached thereto. A vessel or receptacle, 13, adapted to contain quicksilver or some other buoying medium, is adjustably supported beneath the arm 11, preferably by a bracket, 14, into which vessel is inserted a rod or pencil, 12, made of wood or other light material, with a small metal shaft extending through it lengthwise, said shaft floating endwise in the quicksilver, and being held in avertical position by the small neck of the vessel 13. The quicksilver being connected with onepole of a battery, and with no electrical connection with the diaphragm except through. the arm 11 and contact-point 8, this pencil 12 becomes a floating electrode, and the diaphragm 5 is connected through the primary of an induction-coil with the other pole ofthe battery, and the line wire is connected with the secondary of the induction-coil and with the ground. Vhen the floating electrode is in place, the small shaft of metal therein is exposed at its upper end, and the free end of the metallic arm 11 rests thereon in substantially a horizontal position, as shown in Fig. II. The vessel 13 may be held at any desired elevation in the bracket by an adj ustingscrew located beneath the vessel and turned up against it through a threaded hole in a projecting arm to adjust the pressure of the floating electrode against the arm 11 with more or less force, and this pressure may be regulated to any desired degree, and the greatest nicety and delicacy of movement of the arm 1.1, spring 9, and contact-point 8, be obtained.

I am aware that an adjustable mercury-receiver, to contain mercury and a floating electrode, has heretofore been used in connection with a lever or arm in telephonetransmitters, as shown inv patent to G. M. Hopkins, of Au gust 17, 1880, and I do not claim the same; but,

Having thus described my invention, what I claim as new is The combination, in a telephonetransmit- .ter, of a diaphragm provided with a carbon button, a pivoted arm, a spring secured to the pivoted or rocking part of said arm and provided at its upper end with a contact-point, a vessel to contain a buoying medium, and a floating electrode contained therein and supporting the free end of said-pivoted arm, substantially as described.

JAMES A. LAKIN.

itnesses H. B. LEWIS, S. S. CONNER. 

